Automatic damper mechanism for baling staple fibers



May 6, 1969 D, CCANLESS ETAL 3,442,204

AUTOMATIC DAMPER MECHANISM FOR BALING STAPLE FIBERS Filed April 4, 1966Com'muous FILAMENT EXTRUSION COLLECTION OF PLUEALITY or- CONTINUOU$FlLAMENTs To Foam Tow BUNBLE CmMPmG Tow iLAM ENT&

STAPLE MANUFACTURE (Q CUTTING CRlMPEb Tow To FORM STAPLE F1 seas)FORMING BALES 0F STAP LE FIBERS FORSHIPMENT To 5TAPLE- PRocEssoR STAPLEPEocEssmq To Foam STAPLE YARN (e. .WQRSTEb SYSTEM,

TTON SYSTEM) STAPLE YAR N STUART b. MQCANLess and Izvm PLOWbE-N Mi miATTORNEY l9 INVENTORS:

United States Patent 3,442,204 .AUTOMATIC DAMPER MECHANISM FOR BALINGSTAPLE FIBERS Stuart D. McCanless and Irvin V. Plowden, Rock Hill, S.C.,assignors to Celanese Corporation, New York, N.Y., a corporation ofDelaware Filed Apr. 4, 1966, Ser. No. 539,841 Int. Cl. B30b 9/30 U.S.Cl. 100--35 6 Claims ABSTRACT OF THE DISCLOSURE Staple fiber bales areprovided of more uniform dimensions and density by depositing the fibersin a more uniform layer. Such a layer is provided by altering theforward course of travel of the fibers during the conveying thereof, andjust prior to their being condensed into a layer over some predeterminedsequence and period of time.

This invention relates to the manufacture of staple fibers fromcontinuous filaments. It particularly relates to an improved process andapparatus for baling staple fibers to obtain bales of relatively uniformdimensions an density and of increased overall weight.

While man-made continuous filaments or fibers have, as is deemed wellknown, many advantageous properties, such as tenacity, etc., they alsolack some of the desirable properites of natural staple fibers, e.g.,cotton, wool, and the like, such as cover, bulkiness, hand, insulatingproperties, etc. In an effort to attain the desirable advantages andproperties of both man-made and natural fibers, a considerableproportion of man-made continuous fiber production is cut into staplefiber lengths and is thereafter processed as staple fibers, both intextile and nontextile end-uses. To provide the textile industry withman-made staple fibers, the man-made fiber producer cuts a continuousfilament tow, i.e., a bundle of continuous filaments, into staple fiberlengths, as desired by the staple fiber processor, of from less thanabout one inch to as much as fifteen inches. Staple fibers or bunchesthereof, after leaving the tow cutting operation, are conveyed by an airstream through a conveyor duct and are condensed or deposited as a layerof randomly arranged staple fibers on a rotating condenser screenpositioned above a bale press box. The fibers are picked-off therotating condenser screen by pick-up rolls, drop into a conveyor chuteand are periodically kicked into the bale press box. After each kicking,the staple fibers kicked into the bale press box are tamped by ahydraulic ram or tamper. When the required volume of fibers asdetermined by a volume control device, such as the maximum pressureallowed to be exerted on the staple fibers in the bale press box by thetamper or the like,-has been deposited in the bale press box, the bodyor volume of fibers isthen pressed by a hydraulic ram to the desiredfinal volume. The density limits, i.e., the weight of fibers in thefinal volume, is determined by the handling characteristics of thestaple fibers during subsequent staple processing. Thestaple fibers arethen baled, much like cotton or woolen staple fibers, in rectangularcardboard carton wrapped with steel bands, and the bales of man-madestaple fibers are then shipped to the staple fiber processor who eitherprocesses thestaple fibers through one of the commonly known staplesystems to form a staple fiber yarn or through a nontextile system toform e.g., fibrous batting for use in comforters, quilted linings,furniture batting and the like.

The problem with which our invention is concerned originates with thebaling operation which is attendant with numerous problems anddisadvantages. The bales of manmade staple fibers produced heretoforeare quite often non-uniform in size or dimensions, e.g., a bale insteadof having relatively flat surfaces, as is desired, may often have one ormore surfaces which bulge in the middle or which bulge or protrude moreon one end than the other, or the like, resulting in a number ofproblems, as hereinafter mentioned. As is readily apparent, a bale whichis non-uniform in size must necessarily be non-uniform in density. Forexample, a bulge in the center of the bale means that a greater volumeof fibers has been deposited in the center of the bale than in the outeredges. Upon pressing, the fibers in the center of the bale are thereforecompressed or densified to some degree before the fibers in the outerportions of the bale are subjected to compression. This non-uniformdensity makes for problems in subsequent staple processing, e.g., areasof staple fibers of high density are more diflicult to open, i.e.,separate fibers from one another, than are areas of lesser density.

Moreover, bales of staple fibers having uneven dimensions frequentlyresult in damage to the baling press, need be rebaled, or even in someinstances scrapped. In addition to press damage, rebaling costs and thelike, uneven bales and bales which vary from one another over arelatively wide weight range result in added storage, handling, andtransportation costs. Not only are there economic considerations relatedto uneven staple fiber bales, but severe safety considerations are alsoinvolved. An uneven bale can kick the press doors open violently whenthey are released. Also, the metal bands of an uneven bale, apparentlybecause of highly localized stresses in the bands, are prone to breakwhen the bale is being handled, and personnel handling the bale orstanding close by are therefore subject to serious injury.

In order to produce bales of uniform size and dimension and uniformdensity the staple fibers must be evenly distributed across the balepress box, as is more fully explained hereinafter.

It has been determined that uneven bales and bales of non-uniformdensity result from the lack of a balanced flow condition, i.e., insteadof fibers being uniformly distributed over the rotating condenser screenor roll, they are found to be deposited more on one side than the otheror to deposit more in the middle of the roll than on the side, or thelike. The flow is found to be sensitive to anything that :alfects theair flow in the conveying system, which may, to name a few reasons,include the condition of the exhaust filters, lack of cleanliness of theconveyor and exhaust ducting, condition of the condenser screen seals,cleanliness of the condenser screen, and the like.

In an endeavor to provide more uniform distribution of the staple fiberson the condenser screen, and therefore more uniform bale density anddimensions, the flow of fibers through the conveyor system has been, inthe past, subjected to a damping force of air, hereinafter more fullyexplained. The staple fiber conveyor duct, through which air is beingpulled and entrained therewith staple fibers, is provided about theperiphery thereof, with a plurality of holes or ports of about fourinches diameter. A metal sleeve having one port or hole located thereinof approximately the same diameter as the ports in the conveyor duct ispositioned on the conveyor duct over the ports or holes therein. Whenthe flow of fibers is observed to deposit unevenly on the condenserscreen or roll the hole in the sleeve is then manually rotated andaligned with a suitable hole in the conveyor duct. The theory is thatthe flow pattern of fibers being deposited onto the condenser screen canbe altered or changed by aligning the two holes, i.e., the hole in thesleeve and the one in the conveyor duct, whereby a stream of air ispulled into the conveyor duct which, because the con veyor duct isalways under negative pressure, acts as a force opposed at substantiallyright angles to the conveying flow of staple fibers, thus causing thefiber deposition pattern on the condensing roll to be altered. As onecan readily see, this procedure of attempting to alter the flow patternis wholly a trial and error operation. Even though operating personneldevote a considerable amount of time manually adjusting the sleeve,staple fiber bales are still consistently produced with non-uniformdimensions and density, varying bale weights, and the problems anddisadvantages above-mentioned.

It is, therefore, the primary object of this invention to overcome theproblems and disadvantages above-mentioned.

It is also an object to provide a process for consistently producingstaple fiber bales of relatively uniform dimension and density.

It is another object of this invention to provide a process forconsistently producing a plurality of staple fiber bales, each of whichhas relatively the same overall bale weight.

It is a further object to produce staple fiber bales having an overallincreased density over those currently available for a specific staplefiber.

An additional object is to provide new and improved apparatus for balingstaple fibers whereby staple fiber bales having relatively uniformdimension and density are produced.

Other objects will become apparent in the detailed description whichfollows, reference being had to the accompanying drawings, wherein:

FIGURE 1 shows a block diagram describing staple fiber manufacture andprocessing thereof to a staple fiber yarn;

FIGURE 2 is a perspective of a baling operation;

FIGURE 3 shows a damper which has been used heretofore; and

FIGURE 4 is a perspective view showing the damping apparatus accordingto our invention.

It has now been determined that the foregoing objects can beaccomplished by allowing or causing a side flow of air to enter theconveyor duct substantially at right angles to the flow of staple fibersso that it will hit or impinge upon the flow of fibers periodically at aplurality of predetermined points around the periphery of the flow offibers according to some predetermined time sequence and length of time.

Referring now more specifically to the drawings, in FIGURE 1 there isshown a block diagram, which is deemed self-explanatory, describing thevarious operations involved in the manufacture of man-made staple yarns.In FIGURE 2 is shown, indicated generally by reference numeral 1, anapparatus for forming a bale of man-made staple fibers.

As indicated in FIGURE 1 of the drawing, filaments are extruded throughspinnerettes according to known procedures (by apparatus not shown) anda plurality of these filaments are gathered together and are formed intoa tow bundle, i.e., a bundle of filaments. The filaments are thencrimped and are subsequently cut or broken to form fibers of staplefiber lengths according to conventional and well-known techniques. Thestaple fibers are then conveyed by air, in a direction indicated by thearrows (FIGURE 2) through a conveyor duct 2, transition ducting 3 andimpinge upon and are distributed or deposited in a layer in relativelyrandom fashion upon the surface of perforated condenser screen 4rotating in the counter clockwise direction, viewed from the left sideof the figure, and as indicated by the arrow. The staple fibers, notshown for purposes of clarity, are held on the surface of rotatingscreen 4 due to the negative pressure which exists in the system createdby the air being pulled through conveyor duct 2, transition ducting 3,rotating screen 4 via perforations 5 therein, and passageways 6, 7 by ablower or fan, not shown in the drawing. The fibers are picked-offrotating screen 4 by pickup rolls 8 and fall onto a chute, which forsake of clarity and because it forms no part of the invention, is notshown in the drawing. The staple fibers are then kicked or pushedaccording to conventional techniques known to those in the baling artand fall into bale press box 9 in a relatively random fashion to formlayers of staple fibers indicated generally by reference numeral 10.Between each kicking operation, the staple fibers in bale press box 9are tamped by a hydraulic tamper or the like (not shown). When thedesired volume of staple fibers has been collected in the bale pressbox, which volume in turn is known to result in a desired bale densitylimit upon subsequent pressing to a certain set pressure, the staplefibers in the bale press box are then, according to usual balingtechniques, compressed and baled, i.e., wrapped in cardboard and burlapand banded with steel. bands.

Our invention will now be more fully described with reference being hadfirst to the device used heretofore. Prior to transition ducting 3,there is located in conveyor duct 2 a plurality of holes, ports oropenings 11 around the periphery thereof as is shown in FIGURE 3,through which air may be drawn into conveyor duct 2. Heretofore, in anattempt to alter the general flow of fibers through duct 2 and thereforethe distribution of fibers on perforated condenser screen 4, the dampingapparatus, as is shown in FIGURE 3, has been used. The sleeve 12, havinga single hole 13 therein, of approximately the same size as the holes 11in conveyor duct 2, is manually rotated or positioned on the conveyorduct as indicated by the arrow so that the hole 13 on the sleeve 12matches with a suitable hole 11 in the conveyor duct 2. Air is thenallowed to be pulled into the conveyor duct 2 in an attempt to influencethe flow pattern and distribute the staple fibers on the surface of thecondenser screen 4 in the desired manner.

As is now deemed quite apparent, such operation and apparatus, asabove-described, results in a very unstable distribution of staplefibers onto rotating condenser screen 4; hence, into the bale press box9. As before explained, the flow pattern of air and entrained fibersthrough duct 2 onto screen 4 depends upon numerous factors, e.g.,condition of blower air filters, cleanliness of duct 2 and exhaustducting, condition of the condenser screen seals, cleanliness of thecondenser, the cutter being used, speed of the cutter, leaks in thesystem, and the like. Any one of these factors can cause a change in theflow pattern immediately after operating personnel have positionedsleeve hole 13 over a particular duct hole 11 in order to compensate forprevious erratic flow, i.e., uneven distribution of staple fibers on thecondenser 4. Operating personnel have, in the past, spent a considerableamount of time in manually adjusting sleeve 12 to alter the flow patternof the staple fibers without attaining any substantial better uniformityof bale dimensions or density than without such apparatus.

It has been concluded therefore that there are so many variables thatconstantly and continuously influence the flow pattern of staple fibersin the conveyor duct, and therefore deposition onto the condenser thatany instantaneous alteration therein cannot be adequately compensatedfor by a single stepwise procedure such as is provided for by the damperdescribed above and which is shown in FIGURE 3.

We have now discovered, however, that a stable fiber bale of relativelyuniform dimensions and density and of substantially greater overallweight can be produced by periodically and systematically allowing airto enter the conveyor duct 2 at substantially right angles to the flowof staple fibers from various locations around the duct periphery oversome controlled sequence and period of time. Not only can bales ofgreater uniformity be produced with respect to shape and density but,quite unexpectedly, and contrary to popular belief, bales of greateroverall weight process as well, and in most instances better, duringstaple processing than do bales of lesser overall Weight. Apparently,and we do not wish to be limited by this theory, the better performanceof the heavier bales of staple fibers, attained as a result of theinvention herein described, is the result of more uniform density. Thetight or hard spots existing heretofore in staple fiber bales areeliminated by our invention. Moreover, the peak density, as determinedby the thumb test and which is hereinafter more fully described, is lessthan in the staple fiber bales produced heretofore.

According to our invention, there is shown in FIGURE 4 an automaticdamping system for uniformly distributing staple fibers onto perforatedcondenser screen 4. Conveyor duct 2 is provided with a plurality ofholes or ports, preferably three in number, as is shown in the figure.Also, quite desirably, two of the ports 14, 15 are directly opposed toone another and are more or less in alignment with the axis of condenser4 while the third port 16 is intermediate the two opposed ports 14, 15at the bottom of conveyor duct 2. This allows air to enter conveyor duct2 from either side and the bottom of the duct 2 just ahead of transitionducting 3. It is preferable to have the ports at no greater substantialdistance from the beginning of the transition ducting than the diameterof the conveyor duct. Otherwise, the influence of the air flow throughports 14, 15, 16 upon the flow pattern of staple fibers is reduced to anundesirable degree.

Although the diameter of the ports and the number thereof may depend tosome extend upon the size of the conveyor duct, air flow, etc., it hasbeen determined that for a conveyor duct of about fifteen inches, threeports of about four inches diameter are preferable. Of course, it isrealized that the port size may be smaller with a greater numberthereof, or that a greater number of ports may be required with less airflow in the system, and the like.

In each of the three ports 14, 15, 16 (FIGURE 4) there is located adouble acting air cylinder 17, 18, 19, each of which is controlled by a4-way solenoid valve (not shown) according to conventional controltechniques to reciprocate plungers 20, 21, 22 whereby valves 23, 24, 25attached thereto can be opened to allow air to enter into conveyor duct2 or closed to prevent air from entering the duct. The three solenoidvalves, above-mentioned, are in turn controlled by a conventionalthree-circuit cam timer (not shown). The length of time that each portis open can, of course, be varied by setting the timer, which may rangefrom as little as about ten seconds to as much as about one minute ormore, with a maximum of five minutes, however, a period of thirty toforty-five seconds has been found highly preferable.

If staple fibers are allowed to collect on one side of the bale pressbox for too long a period of time, a layer of staple fibers in the shapeof a wedge is formed which makes for difficulties in subsequentpressing. Even though an equal weight or layer of fibers is allowed todeposit on the opposite side of the bale press box, the pressing problemremains. When pressure is applied to the bale, the bale does not holdtogether properly. It slips apart upon being pressed much like twowedges, which are superposed to form a cube, do upon being pressed. Foroptimum results, the ports 14, 15, 16 are opened and closed in acontinuous repeating cycle as shown in the table below:

Units of time Port 1 2 3 Close..." Close. Open Do. ...do... Close Open.

the invention in its broader aspects is not to be construed as limitedthereto.

EXAMPLE A cellulose acetate dope comprising cellulose acetate in acetonesolvent was extruded in a metier in conventional fashion through amultihole spinnerette having circular holes to produce a plurality ofcontinuous filaments having a filament denier of about 8.0. Thefilaments from several metier positions were assembled together in knownfashion to produce a bundle of filaments or tow having a total denier ofabout 288,000. The tow bundle was crirnped in the usual fashion and thenwas forwarded to a cutting position where a knife cut the tow intoapproximately 1 inch staple fibers. The staple fibers were then conveyedby air through a conveyor system to a bale press box and were pressedunder a pressure of about lbs./ in. and baled into bales of staplefibers, A damper, according to our invention, was operated to open andclose the ports 14, 15, 16 in a continuous repeating cycle, ports 14, 15being open for approximately 40 seconds while port 16, the bottom port,was open for about 10 seconds. A bale of staple fibers was producedhaving relatively uniform dimensions of about 25" x 49" x 43" and havinga relative uniform density of about 17 pounds per cubic foot. In all 278bales were produced resulting in no non-uniform bales, hereinafterfurther described. The bales were found to have an overall weight ofabout 475 :35 pounds. Heretofore, the same size bales had an overallweight of only about 400135 pounds. Quite unexpectedly, no adjustmentswere required in the cycle established for operation of the dampermechanism according to our invention other than that required in theinitial setting.

The staple fibers were subsequently processed on a Hunter garnettaccording to usual techniques into both 17 ounce and 20 ounce per yardbatting 81 inches wide. Contrary to expectations, the staple fibers,although from bales of much greater overall weight than usuallyprocessed, processed as well as the lesser weight bales and yielded asuperior web in terms of compression and cohesiveness.

Whether a bale is of uniform dimensions and density or not, as referredto in the above example, and throughout the specification, can bedetermined by the following tests:

(1) Observation.-This is of course the simplest test for determiningbale uniformity. Some bales can readily be discounted as beingnon-uniform. For example, if the bale breaks apart during baling or ifit does not have a good cubic shape, e.g., it is extremely lop-sided, itis then classified non-uniform and must in most instances be re-baled.

(2) Measwement.-This is a more definitive test for determining whether astaple fiber bale is of uniform dimensions or not. In a bale press box,e.g., having dimen sions of 24" x 48" x 42" a bale of staple fibershaving the dimensions 25 x 49" x 43" is desirably produced, thus takingin consideration normal expansion of the fibers in the bale. The bale isstill considered to be of uniform dimensions if it has a good cubicshape even if it expands, however, to as much as 45 inches. Preferablyan expansion to no more than 44 inches is desired. However, if the baleis lope-sided, i.e., varies from about 45 inches at one end to about 41inches on the other end or is 45 inches in the middle and 41 inches onthe end or the like, it is considered non-uniform and must be rebaled.In other words, the bales to be classified of uniform dimensions bymeasurement must not vary at the ends thereof more than plus or minusthree inches of the measurement taken at the middle of the bale,Preferably, they vary less than plus or minus two inches, and quitedesirably vary less than plus or minus one inch.

(3) Thumb test.Staple fiber bales, 'when pressed in various areasthereof with the thumb, are found to be relatively soft in some areasand much harder in other areas when they are not of uniform dimensionsas above described. A uniformly dense bale on the other hand, is ofrelatively the same hardnes throughout.

Although this invention :has been described with particular reference tocellulose acetate staple fibers, it is to be understood, of course, thatit is equally applicable to the baling of any staple fibers, forexample, polyester fibers, nylon, and acrylic fibers.

We claim:

1. In a process for baling staple fibers including the steps ofconveying the fibers in a fluid stream to a condensing zone, condensingthe fibers into a layer of randomly arranged fibers, collecting aplurality of layers of the said fibers, and pressing said layerstogether thereby forming a bale of staple fibers, the improvementcomprising subjecting the fibers in the fluid stream prior to thecondensing thereof to a plurality of forces, said forces being directedin a direction approximately perpendicular to the fiber containing fluidstream whereby the forward direction of the fibers is altered and a moreuniform layer of fibers is condensed, thus resulting in a bale ofrelatively uniform dimensions and density.

2. Process according to claim 1 wherein the fluid stream of :fibers issubjected to said forces over some predetermined sequence and period oftime.

3. Process according to claim 1 wherein the plurality of forces are aplurality of streams of air.

4. Process according to claim 3 wherein said air streams are locatedequidistant around the periphery of the fiber containing fluid conveyingstream.

5. Process according to claim 3 wherein two of said air streams aredirectly opposed to one another, while the third air stream isinterposed intermediate said two streams, the flow of each of said airstreams being over a predetermined sequence for a predetermined periodof time, whereby the fibers are uniformly distributed on the condenserand hence the bale box to form a bale of staple fibers of relativelyuniform dimensions and density.

6. In combination with apparatus for baling staple fibers comprising apress means, a bale press box, condenser means, and means for conveyingsaid fibers in a fluid stream to said condenser means, a means' foruniformly distributing the fibers in the bale press'box whereby a baleof relatively uniform dimensions and density is provided, said lastnamed means comprising a conveyor duct having a plurality ofspaced-apart holes arranged around the periphery thereof, valve means ineach of said holes, and timing means to open and close each of saidvalves over a predetermined time sequence whereby fluid is allowed toenter the conveyor duct, thereby to alter the forward direction of thefibers in the conveying "fluid stream.

References Cited Caughlin 19.- l56.4

PETER FELDMAN, Primary Examiner."

